package com.atguigu.gulimall.cart.interceptor;

import com.atguigu.common.constant.AuthServerConstant;
import com.atguigu.common.constant.CartConstant;
import com.atguigu.common.vo.MemberResponseVo;
import com.atguigu.gulimall.cart.to.UserInfoTo;
import org.apache.commons.lang.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * 拦截器（用于对Controller方法的拦截）
 *
 * @Description:
 * 在执行目标方法之前，判断用户的登录状态.并封装传递给controller目标请求
 *
 * @author: kaiyi
 * @create: 2020-09-12 11:14
 */
public class CartInterceptor implements HandlerInterceptor {

  public static ThreadLocal<UserInfoTo> toThreadLocal = new ThreadLocal<>();


  /***
   * 目标方法执行之前
   *
   * @思路：
   * 如果用户登录了，则有userId,如果用户没登录则只有userKey
   *
   * @param request
   * @param response
   * @param handler
   * @return
   * @throws Exception
   */
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    UserInfoTo userInfoTo = new UserInfoTo();

    HttpSession session = request.getSession();

    //获得当前登录用户的信息
    MemberResponseVo memberResponseVo = (MemberResponseVo) session.getAttribute(AuthServerConstant.LOGIN_USER);

    // 将数据提前封装
    if (memberResponseVo != null) {
      //用户登录了
      userInfoTo.setUserId(memberResponseVo.getId());
    }

    Cookie[] cookies = request.getCookies();
    if (cookies != null && cookies.length > 0) {
      for (Cookie cookie : cookies) {
        //user-key
        String name = cookie.getName();
        if (name.equals(CartConstant.TEMP_USER_COOKIE_NAME)) {
          userInfoTo.setUserKey(cookie.getValue());
          //标记为已是临时用户
          userInfoTo.setTempUser(true);
        }
      }
    }

    //如果没有临时用户一定分配一个临时用户
    if (StringUtils.isEmpty(userInfoTo.getUserKey())) {
      String uuid = UUID.randomUUID().toString();
      userInfoTo.setUserKey(uuid);
    }

    //目标方法执行之前
    toThreadLocal.set(userInfoTo);
    return true;
  }

  /**
   * 业务执行之后，分配临时用户来浏览器保存
   *
   * @param request
   * @param response
   * @param handler
   * @param modelAndView
   * @throws Exception
   */
  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    //获取当前用户的值
    UserInfoTo userInfoTo = toThreadLocal.get();

    //如果没有临时用户一定保存一个临时用户
    if (!userInfoTo.getTempUser()) {
      //创建一个cookie
      Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
      //扩大作用域
      cookie.setDomain("gulimall.com");
      //设置过期时间
      cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
      response.addCookie(cookie);
    }

  }

  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

  }
}
